U.S. patent application, Ser. No. 09/131,022, filed on Aug. 7, 1998 now U.S. Pat No. 6,007,952, and entitled, APPARATUS AND METHOD OF DEVELOPING A LATENT CHARGE IMAGE, by D. P. Ciampa et al., describes an apparatus for developing an electrostatic latent charge image on a photoreceptor that is disposed on an interior surface of a faceplate panel of a cathode-ray tube (CRT). The developing apparatus includes a developer tank having a back electrode and two pairs of panel skirt sidewall shields. The back electrode has a potential applied thereto that establishes an electrostatic drift field between the back electrode and the photoreceptor on the faceplate panel. Triboelectrically charged phosphor materials are introduced into the developer tank and directed toward the photoreceptor on the faceplate panel by the electrostatic drift field shown schematically in FIG. 1. The panel skirt sidewall shields are disposed around the peripheral sidewall of the faceplate panel to prevent the triboelectrically charged phosphor materials from reaching the sidewall of the faceplate panel. The panel skirt sidewall shields are formed of a suitable insulative material, such as ultra high molecular weight (UHMW) polyethylene. As shown in FIG. 2, to prevent the accumulation of phosphor particles on the shields, the shields are primed with positive charges that cancel the normal component of the electric field at the shields, so that the shields will not attract and accumulate the positively charged phosphor particles. While priming with positive charges reduces the accumulation of phosphor particles, it does not provide a means for controlling the amount of phosphor material deposition at the edge of the photoreceptor or of ensuring that the weight of the phosphor materials deposited in the peripheral areas of the photoreceptor is the same as that deposited in the central portion thereof A need therefore exists for a developing apparatus having means to provide uniform phosphor deposition while preventing an accumulation of phosphor materials on the shields.